With the classic poppetvalvestyle engine, air cannot make a straight shot into the cylinder. The porting and polishing process is broadly the same for all cylinder heads. Progress porting a set of 241 heads for a single turbo build. The 241 and 243 heads or ls1 and ls6, respectively are perfect examples. I for one have zero experience with head porting, and a pair of 675s that id like to try and improve. Cnc port ls1truck 241, 806, 853 cylinder heads pair katech. Cathedral port cylinder heads have been mistakenly dismissed by many in lsseries circles for being oldtech. With over 30 years of experience, we have the knowledge and technology to ensure that you dominate at the racetrack. Just like the title says, how much more hp gain will i have on my car if i. Typical gains are 3545rwhp over the unmodified 241, and most 346cid ls1s manage 430460rwhp sae. Porting cylinder heads allows you to flow more air and unlock hidden. Cylinder head services livernois offers something that most of our competition just cant match, complete in house cylinder head development from start to finish.
Small block chevy ls cylinder heads by casting number. Understanding the characteristics of airflow while maintaining the integrity of the head take time to learn. Performance cylinder heads enhance the airflow into your engine, giving you improved power and torque. David vizard is a revered engine builder, technical writer, and author. Fed ls1 243799317241 cathedral stage 1 cylinder heads set. Surprising hp numbers from our stock ls cylinder head test.
For the record, pocket porting heads reworking and blending the seats into the first 2 or so inches of the port is all about focusing on rule number1, to the exclusion of almost all else. Before you attempt porting you should read up about what you are trying to achieve and watch a few videos. Preplanning reiterating, the internet is a valuable tool for the novice. It takes a craftsmans touch to shape the surfaces of the head for the optimal flow characteristics and the best performance. Two myths arose from this era of ignorance regarding port flow. There has to be a bend in the port to accommodate the valve stem and, worst of all, the air must make its way around the head of a valve.
The cnc ported ls9 heads blend the engineered strength of the ls9 cylinder head design, which is constructed with a356t6 aluminum alloy, with the airflow enhancements provided by gms extensive testing. Here is an area where there is a tremendous amount of potential for success and also failure. If you dont believe me, just search online for cylinder head porting more harm than good and view the multiple pages of results. The total area of the restricted portion is smaller than the ported j heads in the link. This procedure was seen as something of a black art, best left in the hands of the greatest of gearhead alchemists. The cylinder head shop carries out porting and gas flowing for all 4 stroke, motorcycles, automobiles and others. May 08, 2015 cylinder head porting operates under a pretty simple premise. Without the proper relationship of valve head to bowl diameter, flow suffers. Few other engine builders have the same level of knowledge and skill porting engine heads as david vizard. So far i have covered a lot of technical details that could be described as peripheral.
The port volumes were within a couple of ccs of the 241 ls1 heads, and the peak flow differed by around 5 cfm despite the 706 heads having a. They are available in double cut and now some are available in aluminum cut. How much does the bore size matter when flow testing. Ls1 241 head bowl blend porting double cut burr work youtube. At the end of the day, pocket porting may not produce the fastestlooking set of heads or the most photogenic, but the results can be very satisfying. Sep 21, 2015 complete cnc porting on a 5axis machine makes these some of the highestflowing factory heads ever. We are undoubtedly south africas leading cylinder head specialist one stop shop and are capable of preparing very hightech quality heads. There are a lot of shops that offering porting, or cnc porting, or cylinder head machining. While intake port volumes are a valuable guide in cylinder head selection, remember that port volume is not necessarily proportional to port flow, and that just because one design has 340cc runners and another has 320s, that doesnt mean that the larger head flows more air or makes more power, although that is usually the case.
In fact, he has authored more than 30 highly respected engine building and automotive books, penned about 4,000 magazine articles, and contributed scores of web pieces to popular sites. An intimidating task for the novice, the guidance of a seasoned engine builder can unlock the mysteries of head porting. Porting demands the right tools, skills, and application of knowledge. However, their thin cross section allows for a highvelocity and smallervolume runner design with excellent flow. Sloppy mechanics wiki lsx head cast numbers flow swap. Gms ls engines are the hottest thing to hit the scene since chevy debuted the first smallblock back in 1955. Our long shank burs are manufactured with a solid carbide bur brazed to a 6 long steel shank. Find great deals on ebay for porting kit and porting polishing kit.
Gm has never been one to underutilize any powerplant, and has a habit of engineering them to accept any number of variant parts designed to optimize performance, cost and fuel economy. Cylinder head design, porting, and repair has been a main focus for the stiegemeier team since 1979. We can also supply you with a matching camshaft and intake. One way to squeeze out a few more horsepower even after porting. The chevy small block, among its many virtues, has always maintained a fan base due to a certain quality. Mar 29, 2017 the cncported ls9 heads blend the engineered strength of the ls9 cylinder head design, which is constructed with a356t6 aluminum alloy, with the airflow enhancements provided by gms extensive testing. Cylinder head porting refers to the process of modifying the intake and exhaust ports of an internal combustion engine to improve the quality and quantity of the air flow.
The 706 heads bested the 241 heads by roughly 10 hp. Ask away, jeff smith, pocket porting, port matching, porting. Our stage 1 ported gm cathedral port porting services are exactly what your ride needs to. From a heads cam ls build to a moderate power adder street car. May 08, 2015 theres no question cylinder head porting can be a very effective way to improve the volumetric efficiency and overall airflow capabilities of any cylinder head. The port is them run through preliminary tests on a flow bench. Sac engineering successfully gas flowed more than 20 000 cylinder heads over the past 33 years and have built at least 2000 very special raceready cylinder heads. Find great deals on ebay for porting tools and cylinder head porting tools.
Everyday low prices and free delivery on eligible orders. In this groundbreaking book, porting master and engine building wizard david vizard covers all the nuances of porting heads and how to build an affordable flow bench to test the results. Increase airflow through the heads and into the combustion chamber and youve got the potential to make more power, since more air in means more power out. Basic porting techniques for chevy smallblock cylinder heads. Going with the flow a look at ported versus unported ls heads. Why buy a set of heads with the wrong parts when we can build you a custom ported set of heads complete, ready to bolt on with the right parts. For a street car, this design means excellent throttle response, torque and average power. Ultimate ls cathedral port cylinder heads guide ls engine diy. To verify this work, you need to flow test the heads on a flow bench. Our stage 1 ported gm cathedral port porting services are exactly what your ride needs to put the power to the ground. If you go to my thread on porting the slant six head you will find more on this andsome pics. Our stage 1 porting service will include the reuse of the stock vales.
Discussion in the hokey ass message board started by andy, jul 4, 20. The ls6 cylinder heads is essentially a tunedup version of the ls1 head. In addition, we also do flowtesting and will provide camshaft recommendations for your specific performance needs. Below we will provide an easy guide to port and polish cylinder heads. Cylinder head porting has been an overused term for the last 20 years, and despite all the words written about this process, you cant go more than 10 minutes with any group of hot rodders before someone uses the term port and polished, which merely reveals their ignorance on the subject. Part 21 cylinder head porting terms and tools 620 hp 454 big block chevy engine build. Cnc port ls1truck 241, 806, 853 cylinder heads pair. Cylinderhead porting basics for the home enthusiast. Its a job for only the mostskilled of mechanics, but head porting can lead to some impressive power gains if performed properly. The 241 heads have a huge bump around the valve guides. Understanding gm lsseries cylinder heads cartech books.
It includes disassembly, inspection and cleaning, cutting valve seats with a 3angle profile, lapping valves, and replacement of valve seals. How to port and polish big block chevy heads it still runs. Failure to ensure correct print settings may result in template printouts that are not true in. Cylinder head porting refers to the process of modifying the intake and exhaust ports of an. General motors produced seven versions of the ls engine, most of them with. Pricing is for work applied to a pair 2 of cylinder head castings and components you supply unless otherwise noted. The five golden rules of porting cylinder heads part 7. The oem valve job brings your cylinder head back to oem honda specs. Engine porting kit can help your engine generate more power. Mikes racing heads is a full service machine shop that specializes in the high performance motorsports market. More details from a heads cam ls build to a moderate power adder street car.
Typical gains for our cnc work are in the 2030rwhp sae range over the as cast 241. The price listed is for you sending your cathedral port cylinder heads 4. Mar 23, 2015 porting a cylinder head is a mix of art and science. Proper port size to get great flow while staying inside the exhaust manifolds or headers up to 1 78 bowl cut, bowl blend, guide work, blend the short turn, raised port. These burs are for those jobs when you need a little extra reach. Adding the bigger valve probably hurt their ascast js, making the porting look even better. We are stocking distributors for the industries best cylinder head manufactures.
Ls1 241 head bowl blend porting double cut burr work. These tools will help you get the performance you are searching for out of your motor vehicle. Porting cylinder heads generally refers to the process of enlarging the intake and exhaust ports of an engines cylinder heads. Lingenfelter cnc ported cylinder heads have ports and chambers carefully designed to provide the best combination of high flow capabilities and improved port velocity. Its important, but is not actually the handson stuff. Fed ls1 243 799317 241 853 cathedral stage 1 cylinder heads set porting service complete assembled stock rockers. Aluminum exhaust cylinder head porting tool tungsten carbide. At 65cc, the combustion chamber is slightly smaller and more efficient than the ls1. The result is a ten percent improvement over the unported ls9 head. Cylinder head porting head porting basics get more power out of your cylinder heads by following five easy rules. On the basis of observing 1,000s of different heads from all ages of vehicles, and the work of many other tuners on race engines, we have had considerable successes in gas flowing for race engines which also translates to more efficiency and better running for road going machines. High flow more power if you have any questions, please feel free to ask. Whether you race pro stock, super comp, or just want to rebuild your old chevy 350 small block, there are cylinder heads just for you.
Bpedelbrock round port cylinder heads outofthebox bpedelbrock d port ported cylinder heads. Chevrolet performance 19328743 lsseries ls9 cncported cylinder head. We take a very serious and methodical approach to cylinder head porting. Prc cnc porting service cathedral port heads customer. Our current offerings allow you to fit up almost 30 years experience and development in the v8 supercar scene straight to your bay. The ls6 cylinder heads is essentially a tuned up version of the ls1 head. Hand porting cylinder heads on an olds 455 big block with legendary joe mondello. We now have a saenz model 680 flow bench which we all enjoy using.
It has all the bells and whistles and even gives us information that we didnt even ask for. High cr 219cc full cnc porting package the only gm 241. The engine can then breathe easier, resulting in greater power and efficiency. Step by step the smallblock ford has never been blessed with particularly good cylinder heads in its halfcentury service life. The valve guide is also huge and has a taper so the base is really wide. Outling the shaping of the exhaust port including raising the roof. This tech tip is from the full book, highperformance. Cylinder head porting refers to the process of modifying the intake and exhaust ports of an internal combustion engine to improve quantity of the air flow.
The remainder of the intake port, and the combustion chamber are left as cast. The problem wit porting books is that there are none that actually tell other than a novice anything. Cylinder heads, as manufactured, are usually suboptimal for racing applications due to design and are made for maximum durability hence the thickness of the walls. There are enough flow numbers on our website to keep everyone busy for a while. Since the factory l92 cylinder heads were released, one of the hottest topics has been how to convert older cathedral port lsseries. All the aspects of porting stock as well as aftermarket. When milling the cylinder heads you are in turn bringing the valves closer to the piston. Fed ls1 243799317241 cathedral stage 1 cylinder heads. Apr, 2011 this is a fairly simple project that may take you about a day, but will give you a cylinder head with high flow rates. What is cylinder head porting, and how does it increase horsepower. Bes racing engines now offers complete cylinder head packages. Determine what port area you need and try different shapes to get the flow up without increasing the area. Cnc port ls2ls6truck 243, 799, 317, 035 cylinder heads. Higgins cnc ported cylinder heads ls1 241 castings.
Bpedelbrock d port cylinder heads outofthebox butler performance edelbrock cnc head porting sevices. Please call me and we can discuss different options. Lingenfelter cnc ported aluminum cylinder head gm ls1. Now you can get this porting service on your cylinder heads at an incredibly low cost. We have heads for the average bracket racer to the all out competion engine. The later 241 castings featured lighter valves, a more common center valve cover bolt configuration, and several other nuances that make them. Our sst porting is for applications where porting the head is allowed and, because of the application, the cylinder head just doesnt need to be fully 100% ported. This combination provides excellent horsepower gains while maintaining a strong torque curve. These templates are scans of the mopar cylinder head porting templates.
Johnny hunkins photographer david vizard photographer. Cylinder head porting has been an overused term for the last 20 years, and despite all the words written about this process, you cant go more than 10 minutes with any group of hot rodders before someone uses the term port and polished, which merely reveals their ignorance on the subject since polishing a port is something that fell. What is cylinder head porting, and how does it increase. The book doesnt state which hemi heads the figures were obtained from in the book either. It would be in our best interest to say that you need several different bore sizes to accurately flow test, lets say, smallblock chevy heads because when going from 4. There is a lot more here on speedtalk than there is in any book. So if you are going to spend some time on your cylinder heads, learn the techniques for pocket porting and spend your time there.
The short sideask top cylinder head porters if theres much to the shortside turn, the part of the port where the floor turns in toward the valve, and you may just hear, its all in the short. Goodson carries a wide range of professional grade porting and polishing tools and supplies. Porting is usually done to increase airflow and horsepower at high rpm. Cylinder head porting services brzezinski racing products. I also recommend using your tools on a similar material so you can get a feel for the amount that is removed with each pass based on revolution speed, pressure and contact duration. Porting the magnificent w2 mopar muscle magazine hot rod. Cylinder head and porting books page 2 don terrill. This program works on the following head casting numbers. How to increase low end torque by porting heads it still.
The bigger is better approach espoused by oldschool mechanics actually can. David vizards how to port and flow test cylinder heads. The first step is to use the traditional method of hand porting using grinding tools and our past experience and knowledge for shape and sizing. Im offering design and cnc capabilities for your program. Cnc port ls2ls6truck 243, 799, 317, 035 cylinder heads pair cnc porting service list. Typical gains for our cnc work are in the 40rwhp sae range over the as cast 241, and many 346cid ls1s manage 420460rwhp sae with boltons and one of our daily drivable hr cam grinds. The street performance head port and valve job is based on one.